Mitutoyo Corporation

Takeshi Hagino

Yuichiro Yokoyama

Yutaka Kuriyama

Masayuki Nara

Yuto Inoue

Yukata Kuriyama

An uncertainty estimation method including: acquiring first variable values, which are a plurality of variable values included in a function indicating a relationship between a measurement dimension and a maximum permissible length measurement error when a predetermined measurement condition value of a coordinate measuring machine is a first value, and second variable values, which are the plurality of variable values occurring when the measurement condition value is a second value; calculating a maximum permissible length measurement error corresponding to a third value by calculating the variable values occurring when the measurement condition value is the third value on the basis of the plurality of first variable values and the plurality of second variable values; and estimating the measurement uncertainty of the coordinate measuring machine on the basis of the calculated maximum permissible length measurement error.

Method of estimating uncertainty of coordinate measurement

A measurement point determination method for determining the number or an arrangement of measurement points for a measurement apparatus that performs measurement processing of a measurement item at a plurality of measurement points, the method comprises the steps of acquiring a minimum value and a maximum value of the number of measurement points, acquiring a target value of uncertainty for the measurement item of the measurement apparatus, estimating uncertainties when the measurement item is measured by the measurement apparatus using two or more of the numbers of measurement points between the minimum value and the maximum value of the number of measurement points, and determining the number of measurement points of the measurement apparatus on the basis of the target value and the estimated uncertainties.

Measurement point determination method, non-transitory storage medium, and measurement point determination apparatus

A coefficient-of-thermal-expansion measuring device includes: a temperature detector detecting an object's temperature; an optical interferometer measuring an object's length using single-wavelength light; an actual data acquiring unit changing the object's temperature to temperatures and acquiring actual data of the length measured by the optical interferometer at each temperature; a data set generating unit generating pieces of verification data for each actual data by setting an order of interference within a predetermined range, selecting one piece of verification data at each temperature, and generating data sets each containing the selected piece of verification data, the data sets having different combinations of selection of the pieces of verification data; and a judging unit calculating a linear approximation function for each data set, and judging, using an evaluation index value based on differences of the verification data in each data set from the linear approximation function, applicability of each data set.

Measuring device for coefficient of thermal expansion and measurement method for coefficient of thermal expansion

A coefficient-of-thermal-expansion measuring device includes temperature control device, optical interferometer, and control device including: an actual data acquiring unit sequentially changing an object's temperature and acquiring actual data measured by the optical interferometer at each temperature; a data set generating unit generating pieces of verification data by setting an order of interference of the actual data within a predetermined range, selecting one piece of verification data at each temperature, and generating data sets each containing the selected piece of verification data at each temperature; and a judging unit deriving approximation functions with different orders from each data set, determining an evaluation index value based on differences of verification data from each approximation function, selecting a candidate data set with the smallest evaluation index value for each approximation function, and determining whether the candidate data set is the same for each approximation function to judge applicability of the candidate data set.

A step gauge and a reference gauge block are placed in a temperature-controlled chamber in parallel with each other. A temperature of the step gauge is changed to a first temperature and a second temperature using a measurement-target temperature adjuster and the temperature-controlled chamber. A distance between a first surface and a second surface of the step gauge is relatively measured at each of the first and second temperatures with reference to a distance between a first reference surface and a second reference surface of the reference gauge block. A coefficient of thermal expansion of the measurement target is calculated from the length of the measurement target at the first temperature and the length of the measurement target at the second temperature.

Coefficient-of-thermal-expansion measurement method and measuring device for coefficient of thermal expansion

In a spherical shape measurement method for measuring a surface shape, a sphere to be measured is made freely rotatable. The partial spherical shape of each measurement area, which is established so as to have an area overlapping with another measurement area adjacent to each other, is measured at each rotation position, and the surface shape is measured by joining the partial spherical shapes of the measurement areas by a stitching operation based on the shape of the overlapping area. In the state of detaching the sphere from the sphere hold mechanism to which the sphere is freely attachable and detachable, the sphere support table holds the sphere. The sphere is re-held at a different position, so that the shape of the entire sphere can be measured with high accuracy.

Spherical shape measurement method and apparatus for rotating a sphere about first rotation axis and rotating a sphere hold mechanism about second rotation axis orthogonal to first rotation axis

A measurement target and a reference gauge are placed in parallel in an inside of a temperature-controlled chamber. After an interior temperature of the temperature-controlled chamber is set at a first temperature, a relative measurement of a length from a first surface to a second surface of the measurement target is performed with reference to a length from a first reference surface to a second reference surface of the reference gauge. Then, the interior temperature of the temperature-controlled chamber is set at a second temperature and a relative measurement of the length from the first surface to the second surface is similarly performed with reference to the length from the first reference surface to the second reference surface. A CTE of the measurement target is calculated based on the length of the measurement target at the first temperature and the length of the measurement target at the second temperature.

Coefficient-of-thermal-expansion measurement method of dimension reference gauge, measuring device for coefficient of thermal expansion and reference gauge

A temperature-controlled bath capable of swiftly changing the temperature of a sample to a target temperature and maintaining the temperature of the sample at a fixed temperature after the temperature change is provided. A temperature-controlled bath includes a temperature changing means, a temperature-controlled chamber, a sample holding chamber, and connection cut-off means. The temperature changing means is disposed in the temperature-controlled chamber, and the temperature of the temperature-controlled chamber is adjusted by the temperature changing means. The sample holding chamber is separated from the temperature-controlled chamber by a thermally conducive wall, and contains a sample therein. The connection cut-off means change a connection between the temperature-controlled chamber and the sample holding chamber to a connected state or a cut-off state.

Temperature-controlled bath

A partial spherical shape of each measurement area of a sphere to be measured, which is established so as to have an area overlapping with another measurement area adjacent to each other, is measured at each rotation position, and the surface shape is measured by joining the partial spherical shapes of the measurement areas by a stitching operation based on the shape of the overlapping area. The position at which the sphere is measured is changed and re-held. A positional displacement between half parts of the sphere before and after re-holding, which is caused by an effect of an error owing to the re-holding, is separated into three rotational components. Magnitudes of the three rotational components are quantified by image correlation and the positional displacement corrected. Then, the stitching operation is performed to measure the entire part of the sphere surface.

Spherical shape measurement method and apparatus

A spherical-form measuring apparatus includes a turntable, a holding unitfor holding the sphere, and a probefor measuring a contour of a sphere partof the sphere. The holding unitincludes a base part, a vertical holding partand an inclined holding partwhich are placed at separate positions on the base part. The vertical holding partholds the stem partof the spherewith it set in a direction perpendicular to the turntable. The inclined holding partholds the stem partwith it set in a direction at an angle. The vertical and inclined holding partare disposed such that their axial lines meet at an intersection point P and such that the distance from the point P to the vertical holding partagrees with the distance from the point P to the inclined holding part

Spherical-form measuring apparatus

An abscissa calibration jig of a laser interference measuring apparatus, includes: an image projection unit configured to project an image with a marker; a first support mechanism configured to rotatably support the image projection unit around a first rotation axis passing a predetermined rotation center; and a second support mechanism configured to rotatably support the first support mechanism around a second rotation axis crossing the first rotation axis at the rotation center.

Abscissa calibration jig and abscissa calibration method of laser interference measuring apparatus

A Fizeau interferometer includes: a reference spherical surface; and a measuring apparatus including an intensity obtaining section and a form calculating section, wherein: a focal point of the reference spherical surface is aligned with a center of curvature of the spherical surface in order to set the center of curvature as a center position, and two positions equidistant from the center position are set as a start position and an end position, the intensity obtaining section obtains the intensity maps of the interferograms at n positions at equal intervals; and the form calculating section measures the form of the spherical surface using a phase analysis method in which a coefficient of the intensity maps of the interferograms at an i-th position and a coefficient of the intensity maps of the interferograms at an (n&#x2212;i+1)th position have a same value.

Fizeau interferometer and measurement method using Fizeau interferometer

A spherical-form measuring apparatus which efficiently measures the sphericity and the form of a sphere to be measured with use of the mechanism of a roundness measuring machine, including a turntable, a probe for measuring a contour of a sphere to be measured on an equatorial plane parallel to a surface of the turntable, associated with rotation of the turntable, and a holding unit mounted on the turntable, for holding the sphere to be measured, wherein the holding unit positions the center of the sphere to be measured on a rotational axis of the turntable, and holds the sphere to be measured so that the sphere is rotatable about an inclined axis which passes the center of the sphere and is inclined at the angle in the range of &#x2212;5 degrees-+5 degrees centered on the angle where the sine is 1&#x221a;3 (1 divided by the square root of 3) against the surface of the turntable.

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Tsukuba, Japan

Takeshi Hagino